Signal lamps



March 31, 1970 J. J. BAILEY 3,504,339

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ATTORNEYS 3,504,339 SIGNAL LAMPS John J. Bailey, Chicago, Ill., assignor to Safety Products Company, Chicago, 11]., a partnership Filed Feb. 14, 1967, Ser. No. 616,105

Int. Cl. B60q 1/00 US. Cl. 34084 7 Claims ABSTRACT OF THE DISCLOSURE A signal lamp for emitting flashing signals at a desired rate. A parabolic reflector extends about the axis of the lamp with a space discharge tube at the focal point thereof having means for electrical discharge at a desired pulse rate.

BACKGROUND OF THE INVENTION This invention relates to improvements in Signal Lamps and, more particularly, to lamps that are adapted for use for warning and for indicating signals as, for example, on emergency vehicles and for signalling the presence of obstacles, either moving or fixed.

Heretofore signal lamps to this type have used multiple incandescant lamps, often revolving within a set circle, as within a dome, and usually rotated by a motor for effecting the desired the desired flashing action thereof. The energizing of the rotating lamps and the motor has required a great amount of electric current which, together with the other functions of the motor vehicle, frequently has caused an exhaustion of available battery current in a very short time. While attempts have been made to amplify the available current by special power packs, these have added considerably to the expense of the equipment.

Signal lamps for fixed or moving objects have also frequently employed incandescent lamps supplied with current from a battery. Due to the power demands of such lamps and for the operation of the circuit making and breaking mechanism thereof, an excess of current has been required which exhausts the available battery strength in a short time.

One object of this invention is to overcome these objections to signal lamps used heretofore by providing a more readily visible signal which will be observed at greater distances for emergency and signalling purposes.

Another object of the invention is to simplify and improve the construction of signal devices to enable these to be built sturdily at low cost for effecting the desired degree of illumination and with the desired flashing action, whether installed on a moving vehicle or on a fixed or movable obstruction.

Still another object of the invention is to utilize a parabolic reflector extending circumferentially around a central axis in association with a space discharge tube which will direct illumination from the reflector over a subsantial area. The space discharge tube is mounted to provide light output visible around azimuth extending approximately 35 either above or below azimuth for a total extended area of the desired angle.

SUMMARY OF THE INVENTION Certain embodiments of the invention include a head unit supporting the space discharge tube and reflector and a base or second unit which may or may not be integral with the head unit and which supports the pulse or control means for intermittently energizing the space discharge tube to effect flashing signals when applied to an emergency vehicle or for signalling the presence of obstacles, either moving or fixed.

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The head unit is preferably self-contained and independent of the base unit so as to be removed therefrom or with respect to each other. Provision should be made for electrically connecting these together so as to transmit the desired current from the pulse mechanism in the base unit to the space discharge tube in the head unit.

The reflector is preferably parabolic and may be arranged with the tube in proper relation to direct light onto the reflecting surface or surfaces. Where a full parabolic reflector is made from two half reflectors, these should be disposed back-to-back with the reflecting surfaces extending above and below azimuth through a substantial angle as, for example, an angle of 70.

The parabolic reflector should extend around a center axis and should have a supporting member secured to it upon which the space discharge tube may be mounted.

The base unit encloses the means for intermitting energizing the space discharge tube so as to operate the tube in a flashing signal action, such as may be desirable for an emergency vehicle or for indicating a fixed or stationary obstruction.

DESCRIPTION OF THE DRAWINGS These embodiments are illustrated in the accompanying drawings, in which:

FIG. 1 is a perspective view, showing one form of signal lamp;

FIG. 2 is a similar view, with the top unit partially removed;

FIG. 3 is a vertical section through the lamp;

FIG. 4 is a perspective view of the head unit, detached and removed;

FIG. 5 is a similar view of the base unit, with parts removed;

FIG. 6 is a diagrammatic view of the operating circuit for energizing the space discharge tube;

FIG. 7 is a diagrammatic view of a full wave control circuit therefor;

FIG. 8 is a similar view of a full wave bridge circuit;

FIG. 9 is a similar view of a pulse timing circuit;

FIG. 10 is a diagrammatic view showing a part of the space discharge tube with an electrostatic field for the control electrode;

FIG. 11 is an elevation, partly in section and partly diagrammatic, showing the head unit of a modified form of signal lamp;

FIG. 12 is a similar view, showing the base unit thereof;

FIG. 13 is a diagrammatic view, showing the control circuit for the space discharge tube;

FIG. 14 is a perspective view, partly in section, of a modified form of lamp;

FIG. 15 is a side elevation of a lamp reflector having stepped sections and showing, partly in section, a space discharge tube with respect thereto; and

FIG. 16 is a cross section through a conical lens having serrations curved with respect to the light source.

DESCRIPTION OF PREFERRED EMBODIMENT Referring first to the form of the invention illustrated in FIGS. 1 to 5, this signal lamp comprises a head unit, generally indicated at 1, and a base unit, generally indicated at 2, adapted to be connected together, as hereinafter described, and to be mounted in any suitable position for effecting the desired signal. For example, the lamp may be mounted in a suitable position on an emergency vehicle, such as an ambulance, police or fire vehicle, aircraft, etc. It may be used also as an airport marker or as a runway approach lamp.

The head unit 1 comprises a pair of reflector members 3, each having a closed side 4 arranged adjacent to each other and having outwardly flaring reflective surfaces 5 extending circumferentially around the center axis of the closed sides 4. These are preferably parabolic reflector surfaces and extend through approximately 360 around said center axis and also extend above and below azimuth as, for example, 35 or a total of 70".

A support plate 6 is disposed intermediate the closed sides 4 of the respective reflectors and extends radially outward of the reflective surfaces 5 in the relation illustrated in FIGS. 3 and 4. This support plate 6 and the reflectors are mounted on a threaded shaft 7 that extends upwardly on the axis thereof from a point beneath the base plate 8 of the head unit 1 to a position above the base unit. Nuts 9 are threaded on the shaft 7 on opposite sides of the closed sides 4 of the reflectors and of the interposed plate 6 to hold these parts securely in embracing relation and tightly in position. These nuts may be replaced by other suitable fastening means.

In this form of the invention, I have shown a cover 10 telescoped over the reflector assembly and downwardly to the base plate 8'. The cover 10 may be made of suitable transparent or translucent material to be illuminated from the interior and may be formed of glass, plastic or other suitable material. It is held in place by a nut 9, or by other suitable fastening means, on the upper end of the threaded shaft 7.

Disposed at the parabolic axis of the reflector surfaces 5 is a space discharge tube 11 which extends circumferentially around the head unit 1 substantially 360. The ends of this tube 11 are turned downward, as indicated at 12 in FIG. 4, in side-by-side relation, which end portions enclose the electrodes for space discharge in the gas of the tube. Any suitable or desired gas filling may be used, such as xenon, krypton, etc. The tube 11 is held in place by bracket clamps 13, spaced at intervals around the circumference of the support plate 6, as illustrated in FIGS. 3 and 4.

A trigger or trip wire electrode is indicated at 14, coiled around the tube 11 throughout the major portion of its length for producing the requisite high voltage triggering spark within the tube.

The base unit 2 includes a base plate 14 which may be mounted on any suitable or desired support such, for example, as a vehicle body, or may be set on the ground or on a stationary or movable obstruction according to the use and purpose of the signal lamp. Upstanding from the base plate 14 on diametrically opposite sides thereof are support legs 15 which have a plate 16 supported on the upper ends thereof. A cover plate 17 surrounds the base unit and encloses the operating parts of the signal generating mechanism.

The base plate 8 of the head unit 1 is seated directly upon the plate 16 of the base unit and these plates are connected together by a clamping ring 18 and a clamp screw 19 extending circumferentially around the lamp. This clamping ring 18 embraces projecting edge portions of the plates so as to hold them in proper relation to each other but to permit of ready separation and removal of the head unit upon release of the clamp 18.

One or more aligning pins 20 are carried by the head unit plate 8 and engage in holes or sockets in the plate 16 for maintaining proper alignment and orientation of the head unit with respect to the base unit.

Additionally, contact pins or prongs 21 are carried by the head unit plate 8 to extend through openings in the base unit plate 16 and into contact relation with jacks mounted on the plate 16 so as to effect electrical contact and to conduct current to the electrodes of the space discharge tube 11 and the trigger wire 14. Thus, two separate plugs 21 should be provided for this purpose.

The means for intermittently energizing the space discharge tube 11 is mounted within the base unit 2 and is thus connected through the several jacks 21 with that tube for effecting instantaneous and intermittent illumination thereby. The energizing means may be operated from any suitable source of current, either alternati g current, if

available, or from a suitable or convenient battery supply of various voltages. The electrical supply means have been omitted from the illustration in several of the drawings, except to the extent indicated in FIG. 5.

While available energizing circuits have been known heretofore, any of which may be used for this purpose, we have shown in FIGS. 6 to 9 illustrations of circuits that may be employed. In FIG. 6 a power transformer is indicated at 22 having a source of electric current, indicated at 23, connected therewith. The output from the transformer 22 leads to a rectifier circuit 24. This is shown in FIG. 6 as a double rectifier circuit, although, if desired, a full wave rectifier circuit illustrated at 25 in FIG. 7 may be substituted therefor or the full wave bridge circuit illustrated at 26 in FIG. 8, as load resistances and voltages require.

The output from the rectifier circuit to the space discharge tube 1.1 is controlled by a pulse timing circuit, generally indicated at 27, incorporating variable or fixed relaxation oscillators. A pulse timing circuit 28 is illustrated in FIG. 9 to provide large current handling capacity. These circuits 27 and 28 Will permit pulse repetition rates up to 700 per minute.

Trigger voltages up to 30 kilo-volts are obtained by changing the primary-secondary ratio in the transformer 29 and the capacitance at 30. The capacitance 31 may be adjusted to provide kilo-joules energy output if transformers of proper capacity are provided.

DESCRIPTION OF MODIFIED EMBODIMENTS As shown in FIG. 10 each electrode of the tube 11 may be provided, if desired, with an electrostatic shield of the character described more in detail in Patent No. 2,889,494, granted June 2, 1959. The shield is indicated generally at 32, surrounding the electrode and intermediate the latter and the wall of the tube. The electrostatic shield 32 may be in the form of a collar or other shape of electrostatically charged plastic or ceramic material so that if charged positively the shield will attract particles that are negatively charged, and if negatively charged will attract particles that are positively charged. Thus, these particles are kept from adhering to the walls of the glass envelope and thereby increase the useful life of the light source.

This form of the invention may be used on moving vehicles to provide low, medium or high signals and as an emergency lamp, and particularly for warning or indicating signals that operate in a flashing state. The pulse timing of the flashing interval will depend upon the discharge means provided, whether of a capacitance or a suitable switch. A residual effect from the energy emitted by the high intensity tube can be obtained by the introduction of fluorescent materials in thetranslucent cover 10, as is well known in illumination.

I have shown in FIGS. 11 to 14 a modified form of signal lamp adapted particularly for signalling fixed or movable obstructions as, for example, a street or road obstruction.

As shown in FIG. 14, this form of lamp has a base 40 with an upstanding conical housing 41, either made in one integral piece with the base or separable therefrom, as desired. The housing 41 should be of a suitable transparent or translucent material and is shown in FIG. 14 as being conical, with a part broken away to illustrate the assembly therein. The housing 41 encloses a head unit 42 and a base unit 43 suitably secured therein and may contain a rechargeable battery, either as a part of the base unit 43 or otherwise mounted in the base support 40.

The head unit 42 includes a container, generally indicated at 44, upon which is mounted a parabolic reflector 45., the inner surface of which is reflecting and surrounds a space discharge tube 46 mounted on the container 44 substantially at the center of the angular reflecting surface. The space discharge tube 46 may be of the character described above and is electrically connected with a pulse and rectifier assembly 47 mounted in the container 44.

The base unit 43 encloses the storage capacitors 48 and transformer 49 and associated parts of the pulse generating circuit. These are connected to the pulse and rectifier assembly 47 in the head unit 42 through a suitable cable or other electrical connection 50.

The electric circuit for flashing the warning lamp 46 is illustrated more in detail in FIG. 13 as one embodiment that may be used for the purpose so as to operate the pulse circuit at the proper and desired rate of discharge. This particular circuit may be varied, however, as found desirable according to the rate and time of discharge needed for the purpose.

The components indicated at 57 in FIG. 6 and 57 in FIG. 13 can readily be installed in a module that may be plugged into the lamp in a octal socket, for example. Since the tolerances, as well as the values of the components indicated at 57 or 57' determine the flashing frequency this module becomes a simple, rapid means to change the flashing rate.

I have also illustrated in FIG. 15 a further modified form of lamp wherein a parabolic reflector of inverse truncated form is made with sections, generally indicated at 51, of stepped construction rather than curved, although extending continuously around the longitudinal center axis of the body forming the reflector. The xenon lamp 52, as an example of a light source therefor, is disposed at the axis of the reflector and mounted on a center support 53 extending radially outward from the center section thereof. In other respects, this reflector functions in the manner described above.

In the further modification shown in FIG. 16, I have illustrated the use of a truncated conical freznel lens, generally indicated 54, and having a light source 55 located at the center thereof. The lens is provided with peripheral serrations, indicated at 56, having optically designed surfaces reflecting or refracting the light rays from the light source thereby determining the vetical range above and below the horizontal plane through which the light is visible. The serrations 56 extend horizontally around the conical face of the lens.

While the lamp herein described has many uses, one of its principal uses is for emergency warning lights, as on vehicles, and in stationary positions using a battery as a power source. This lamp would replace the presently used revolving incandescent warning lamp. It would have a very low battery consumption, with a high light intensity of the xenon lamp as compared to an incandescent lamp. At the same time, there is a material reduction in maintenance cost due to the elimination of motor problems and the changing of lamps. The life of a xenon lamp is several times as long as that of an incandescent lamp. It requires no moving parts since it functions as a result of solid state components.

The xenon lamp is made to flash in a full 360 of refiected light from a parabolic reflector which may be made to reflect either above or below the axis of the lamp, or both, according to whether the reflector is of single or double type. This makes use of a ring-shaped lamp which surrounds the reflector and is located approximately at the focal point of the parabola and causes a beam of light to be directed throughout approximately 360 in a horizontal plane and may extend above or below the horizontal plane through approximately 35 Not only is the lamp capable of use on emergency vehicles, but it is also capable of use inside a plastic traflic cone or as a signal lamp around barricades. I have discovered that when the lamp was used within such plastic bodies, the flash decayed slower because the plastic had a tendency to retain the light.

I claim:

1. A signal lamp comprising a head unit including a pair of cup-shaped reflector members each having a closed side with outwardly extending annular parabolic reflective surfaces surrounding an axis extending through the closed side, each of the reflector members having the parabolic axis of the reflective surfaces externally of the surface, said reflector members having the closed sides thereof adjacent each other and with the reflective surfaces extending in opposite directions from a plane normal to said axis, and an annular source of illumination extending around said annular reflectors.

2. A signal lamp according to claim 1 including a support plate mounted between the closed sides of the reflectors, and a space discharge tube mounted on the periphery of the support plate at the parabolic axis of the reflective surfaces.

3. A signal lamp according to claim 1 including means for electrically and intermittently energizing the source of illumination including a transformer having a primary and secondary, and means for energizing the source of illumination from the secondary.

4. A signal lamp according to claim 1, including a plate interposed between the closed sides of the reflector members with the annular source of illumination extending around the periphery of the plate, and means for mounting said annular source of illumination on the periphery of the plate.

5. A signal lamp according to claim 1, including a base unit having the head unit detachably mounted thereon, and means self-contained within the base unit for electrically and intermittently energizing the source of illumination.

6. A signal lamp comprising a space discharge tube and a reflector therefor, and means self-contained within the lamp for electrically and intermittently energizing the space discharge tube, the intermittent energizing means comprising a detachable module assembly that may be removed and substituted for a module assembly of a different flashing frequency.

7. A signal lamp comprising a surrounding lens having a central axis, a parabolic reflective surface inwardly of the lens and having an annular focal axis intermediate the reflective surface and the lens, said reflective surface facing generally radially outward from the central axis of the lens for directing light rays in a generally radial direction, a ring-shaped lamp extending along the focal axis of the reflective surface for concentrating the light from the ring-shaped lamp in a relatively small zone on the lens, and means for intermittently energizing the ringshaped lamp.

References Cited UNITED STATES PATENTS 2,017,716 10/1935 Halvorson.

2,492,837 12/1949 Briggs 240-11.4 X 2,731,577 1/1956 Floyd 24011.4X 2,738,414 3/1956 Davis et al 340-84X 2,936,387 5/1960 Steele et a1. 240-ll.4 X 3,184,585 5/1965 Rouy 2401l.4X

JOHN W. CALDWELL, Primary Examiner M. R. SLOBASKY, Assistant Examiner US. Cl. X.R. 

